The SCC Resistance of 316L Expandable Pipe in Production Environments Containing H2S and Chloride

Abstract

Abstract The market for sand control products is very competitive, which demands that the manufacturer use economical materials and employ efficient designs. This is especially important in expandable sand control screens; this new technology must compete with existing non-expandable screens that are low cost manufacture using commodity-type raw materials. For corrosion resisting sand control screens, a key component to the success of the product is the metallurgy of the base pipe. The alloy selected must provide corrosion performance similar to 13Cr that is typically used as the base pipe in conventional sand screens. 316L (UNS S31603) is a commodity CRA material that provides the necessary ductility and strength for application to expandable screen base pipe. However, its corrosion resistance in the production environment has been questioned by many users. The basis for this concern is corrosion data and experience in non-production environments. Therefore, corrosion testing in simulated production environments is needed. This test program verified the corrosion resistance of S31603 in a mildly sour environment containing 0.50 psi (0.003 MPa) H2S and 50,000 ppm chloride at pH 3.5 and 175 °F (79 °C) as well as established some performance parameters in more severe environments of H2S, chlorides, and temperature. With these data, S31603 can now accepted for many applications where conventional 13Cr completions would be used and also in sour environments that exceed the limits now established for S31603 in ISO 15156/NACE MR0175.